This rifle was designed in the early to mid 1990s by South African arms designer Tony Neophytou, who also took its part in designing the Neostead combat shotgun. Initial development was under the Aerotek name, and later the Mechem division of the DENEL Group, a major South African arms manufacturer, purchased all rights for this design. In the 1998 South African National Defense Forces adopted this weapon and began to purchase it in some numbers. It is also offered for export sales. The NTW-20 is a long range anti-materiel rifle, developed to reach out across wide plains of South African landscape and to deliver substantial firepower in a relatively compact, two men portable package. It is available in two versions, 20mm and 14.5mm, and could be easily converted from one variant to another by simple replacement of the barrel, bolt, magazine and scope, which will take about 1 minute in the field conditions. These two versions had slightly different applications: 20mm version, built around WW2-era German MG-151 aircraft gun round, can deliver high explosive, fragmentation or incendiary shells with good accuracy, so a relatively "soft" targets could be disabled by the blast and / or fragments. When the long range and armor penetration is an issue, the 14.5mm version comes into the play. It is built around another WW2-era round, Soviet 14.5mm high velocity, armor-piercing cartridge, developed for PTRD and PTRS anti-tank rifles and still widely used in Russian KPV / KPVT heavy machine guns on armored cars and in anti-aircraft mounts. While probably not so accurate as the specially developed .50BMG (12.7x99mm) rifles, mostly due to unavailability of the "match grade" ammunition in the 14.5mm and 20mm, NTW-20 offers significantly more terminal effectiveness than any .50BMG rifle / round combination. 20 mm version could be most effective against targets like parked aircrafts and helicopters, command and communications equipment, radar cabins, fuel dumps, unarmored cars. 14.5 mm version will be more effective against armored personnel carriers or relatively large "soft" targets at extended ranges. Anti-personnel work is by no means a primary task for this huge rifle.NTW-20 is a manually operated, rotating bolt action rifle. The barrel is locked by the rotating bolt that has 6 lugs. The barrel along with the receiver could recoil inside the chassis frame against combined hydraulic and pneumatic damping system. Large two-chamber muzzle brake also helps to keep recoil at the acceptable level. NTW-20 is fed from the detachable box magazine, that is inserted from the left side and holds 3 rounds. The rifle could be disassembled and carried in two man-portable packs, each weighting about 12 - 15 kg. One pack carries the frame, stock, butt and bipod while the other carries the barrel, sighting equipmentand magazines. NTW-20 is equipped with a 8X magnification, long eye relief telescopic sight on the quick detachable mount. No open sight are fitted by default. The folding bipod is mounted under the receiver, and a non-folding frame above the receiver serves as a carrying handle and a scope protection bracket.